In industrial production, a valve needs to be used in many places, a handle which can be opened or closed by a manual operation valve needs to be arranged on the valve. In the valve use process, the valve can be operated by mistake, the handle is prevented from rotating due to external force collision and other reasons, and then the valve is mistakenly opened (or closed); once the condition occurs, it leads to the waste of the resources (the medium in the pipeline flows out through the valve), or the normal operation of the system is influenced (the valve is closed incorrectly and the medium cannot be supplied through a valve), seriously, casualties can be caused (poisonous-acting medium flows out of valve). The valve in the prior art does not have a self-locking function when being used, due to the fact that the valve is prone to being mistakenly operated, false opening or false closing can be caused.